(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "The manufacture and properties of iron and steel"

THE BLAST  FURNACE.
47
When the air is 0° C. the temperature of the fire is about 1560° C., while if the blast is 1000° C. it will be 2400° C. Each increase of 100° in the temperature of the air raises the resulting temperature about 80°, whether the scale be Centigrade or Fahrenheit.
SEC. Hi.—Vapor in the atmosphere.—Accompanying are the weather records at Harrisburg, Pa., the figures being averages of the years 1901, 1902 and 1903. The climate is representative of the northeastern portion of the United States. The year is divided into the "wet" half and the "dry" half. The percentage of humidity is about the same in winter as in summer, but the actual amount of moisture in the warm or wet half of the year is about three times as much as in the cold or dry half, while in July the content is nearly six times as much as in February.
Dry half.	Nov.	Dec.	Jan.	Feb.	Mar.	April.	Av'ge.
Temperature ...................	42	30	29	28	44	51	37
Humidity, per cent .............	70	76	74	69	69	62	70
Grains per cubic foot : Saturation .......................	3.08	1.98	1.91	1.83	3.34	4,26	2 73
Actual ...........................	2.16	1.50	1.41	1.26	2.30	2.64	1.88
							
Wet half.	May.	June.	July.	Aug.	Sept.	Oct.	Av'ge.
Temperature ....................	63	68	76	71	65	55	66
Humidity, per cent ............	64	71	74	79	77	72	73
Grains per cubic foot : Saturation .......................	6.17	7.60	9.79	8.31	6.88	4.92	7.28
Actual ...........................	3.95	5.40	7.24	6.56	5.30	3.54	5.33
							
This moisture, when blown into the blast furnace, is decomposed, one kg. of water forming 1-9 kg. of hydrogen and 8-9 kg. of oxygen. This decomposition absorbs a quantity of-heat equal to that produced by burning a similar weight of hydrogen^ 30000 -------. =3333 calories. On the other hand, the oxygen set free unites
9 with the coke.
8-9—0.89 kg. 0+0.67 kg. 0=1.56 kg. CO
producing 1650 calories, the net absorption being 3333—1650= 1683 calories per kilogram or 3030 B.t.u. per pound of water vapor admitted. This absorption of heat immediately in front of the tuyeres must be compared with the creation of heat at the